On Sun, Jul 05, 2015 at 02:12:18PM +0900, Ryota Ozaki wrote: > On Sun, Jul 5, 2015 at 2:35 AM, David Young <dyo...@pobox.com> wrote: > > On Sat, Jul 04, 2015 at 09:52:56PM +0900, Ryota Ozaki wrote: > >> I'm trying to improve use of rt_refcnt: reducing > >> abuse of it, e.g., rt_refcnt++/rt_refcnt-- outside > >> route.c and extending it to treat referencing > >> during packet processing (IOW, references from > >> local variables) -- currently it handles only > >> references between routes. The latter is needed for > >> MP-safe networking. > > > > Do you propose to increase/decrease rt_refcnt in the packet processing > > path, using atomic instructions? > > Atomic instructions aren't used yet, i.e., softnet_lock is still needed. > I will introduce them later. (Using refcount(9) by riastradh would be > good once it is committed.)
I think the main point that David wanted to raise is that the normal path for packets should *not* do any ref count changes at all. Joerg